Pricing out chokes and a question came up. Hammond choke at 20H 600V is $44. Two Triad chokes at (C-7X) 10H 1500VRMS are $11. Was just wondering if, other than the increased resistance, would I be creating problems. Two chokes, same Henries, half the cost. Thanks for any input.

If you're working with a voltage amp...probably not a big deal either way. If you talking about a choke input for a power amp, you want to keep the impedance as low as reasonable and that much inductance will probably have some frequency roll off issues....I'm think wet blanket issues:)granted, the critical current will be more accommodating but you probably won't like the sound. Let me know how it turns out...

in a dual m derived pi filter using oil capacitors then I'd follow that with a shunt regulator using gas tubes. Ray "The gift of imagination is a gift of the Gods imparted to a few who receive innumerable kicks in the a$$ their entire life." Le Corbusier (Charles-Édouard Jeanneret)

Doing the shunt regulator. Going to have to make up my mind on the chokes, I am cramming so many under there already I worry that I won't have the room to ensure that there are no interactions if I buy that many.

and OA3 gas tubes as a shunt regulator. It's early 50s vintage and was made for their recording studio mic preamps and pro radio station equipment. Output is about 380 volts. It used two 20H chokes and rather low value oil capacitors. Yes, space is always a problem for me too. I always choose a chassis that is too small. Ray "The gift of imagination is a gift of the Gods imparted to a few who receive innumerable kicks in the a$$ their entire life." Le Corbusier (Charles-Édouard Jeanneret)

I tend to use Hammond products for the the PS and Lundahl for the signal path. I acknowledge that the lines are blurred between the two but generally the Hammond products have served me just fine and they are from our Northern neighbors...

I have however had good experiences with DAC products from China as far as performance versus dollars...I have had to send a couple of units back because of failure...I'm a cheapo, so my first US made be DAC will made by ME..

The Triads are probably Chinese, thus the cheaper price. Aside from the fact that I don't trust or use Chinese parts, the two series Triads will yield 540 ohms DCR. A Hammond 193C is only 180 ohms. That's a significant difference.

I probably spend thousands of dollars every year to buy products made in the West over Chinese imports. Despite US laws regarding labelling and disclosure of product origin, it's now reached the point where nearly everything I buy online has to be investigated first. That includes motorcycle parts, audio components, DSLR accessories, etc. etc. I can't even bid on eBay in many cases without first asking the seller where a particular switch or capacitor is made. It's worth the trouble to me, but the difficulty increases every year. In local stores such as Home Depot, I now frequently find tools made by companies like Bosch with no country of origin listed, and for which the retailer can find no information, even after calling the US rep. I suspect the day is coming when Western electronic components will no longer be available, or if they are, I won't be able to afford them. When that happens, I'll stop building.

I acknowledge that this isn't the forum for this but, there's the school of thought that every man is an island that has gained an alarming amount of momentum in recent years.

I know that this school has always been there but the basic teachings of Christianity and other similar religions (and just good people) have always been able to keep it in it's place...

I'm afraid that we are close to the tipping point....The devil has gained the edge..$$$$$$$$$...The other interesting development has been the leveraging of the Religious Right as a means of progressing this school.

I am not planning on bread boarding, I only wish I had that kind of patience. I am thinking that an extra bit of money so that I don't have to worry about choke interaction and also have the lower resistance sounds good. My biggest concern now is the suggestion that I don't have enough Mu in the 76's to run a two stage amp and power the 45s properly. I will probably go ahead and build it with the 76s, but a switch to a tube with higher Mu is a distinct possibility down the road.

In Reply to: RE: what?... posted by deathtube 667 on May 17, 2012 at 04:38:23

The #1 influence. Great guys. Jeff helped me build one hell of a 2a3 amp for not a whole lot of money! It's the best amplifier I've built, no contest with anything else I've played around with.

He has been patient with my lack of knowledge and experience and always willing to help. Both guys are stand up good people.

There are other guys that have helped along the way... Kegger from AK has been a big help to me, SET12 from over there too... Douglas around here is probably getting tired of all of my inquires, but yet another great guy and great source of knowledge.

There are other guys around here on the more technical engineering side of things I consider to be a great resource too. They might not agree with Jeff/Dennis however I always try to carefully read what they put out there and consider it.

These guys might not all agree with each other however all of them have been indispensable to me. Lots of others around here like that too, I learn a lot on this site... and a good deal of it is from people that don't much care for subjective evaluations and marketing. ;)

I don't see either of these gentleman as a mentor in the full sense of the word.

I perceive Jeff as passionate, dedicated and very thorough but too lacking in technical knowledge and understanding to be a mentor. Jeff is generous, however, in sharing what knowledge he does possess in his desire to help others. I can well believe you have benefitted from his help.

Dennis, on the other hand, is boastful, invents his own arcane terminology as he goes along (e.g.transfer efficiency), talks in riddles and guards whatever knowledge he may have as if it were a state secret. I don't see that as particularly helpful and certainly not in any way acting as a mentor.

I believe a power supply should have less than 120 ohms resisistance including the chokes, transformer secondary & tube rectifiers feeding an amp requiring 100-140ma current at idle (no signal input). I design for a 50% current increase with 16ms voltage recovery. I hear no difference when compared to ultimate shunt regulated designs. I am also referring to SET amps that are more critical than class A push-pull amps.

I wonder how much of the class A problem (or challenge) is due to having the tube cross into A2 on signal peaks. Most of us probably have the tendency to over-drive our amps. A2 peaks will draw more current and thus cause voltage fluctuations with a high resistance power supply.

If I remember correctly - some have joined 2 chokes together so that their cores were in the same B field making a choke of 4x the inductance. That means the 2 Triads would make a 40H choke. You would have to wire and mount them correctly or their B fields would cancel instead of multiply.

In Reply to: RE: Question posted by drlowmu on May 14, 2012 at 15:40:10

Hey, sorry to get back so late, and I am not one who posts under other monikers. I don't know anything about the arguments going on here. I do appreciate the input. I think it is a two stage amp, from my understanding. At this point I have bought quite a few 76s. I am hopeful that my Bottlehead FPIII is high enough gain that the 76s will run with them well and still be able to feed the 45s properly. My buddy took some Paramours and converted them to 76 feeding a 2a3 and I thought they sounded pretty good. I am not as technical as I would like so I can't offer a good argument for or against it, as I am sure you can. I think, however, that if I am unhappy with the performance of the amp and it doesn't sound good at low levels, that changing the amp over to a higher Mu driver tube should be something we could accomplish, don't you think?

In Reply to: RE: Question posted by Paully on May 16, 2012 at 14:26:40

Paully,

Thanks for posting and clearing up the hoax poster. I should have known better than to answer to someone who has no spine to post their name, nor any manners !!

Yes, you can always swap out a tube if you deem it necessary. I am not familiar with the specific circuit. If it is just two tubes, an input and a output, my comments apply at low level listening, otherwise, if three stage, a Type 76 is "loverly", one of my favs.

In Reply to: RE: Question posted by drlowmu on May 14, 2012 at 15:40:10

Jeffrey,

This is getting silly and I do not accept you apology for trolling in advance. You left your minions floundering below pumping out your religious bilge, yet you remain silent in their defense of some facts that can easily be checked by a simple phone call. (Kimber on wire color)

In Reply to: RE: Question posted by 12AX7's vs. 76 as a driver??? on May 14, 2012 at 20:15:46

My, what a nasty response!! I note you don't have the ba**s to identify yourself or sign with your name or moniker.

Why are you mentioning a 12AX7 ? I did not specifically suggest that to you, did I ?? It is only usable in a DC amp. You were assumptive.

I just inferred "higher mu" than a Type 76. That driver tube choice is left to you, you may have a cap or transformer couple, so select wisely !

I personally do not need to defend black wire at all. That is not what this thread or my post is about. I mentioned black wire and said I don't use it. Others, notably, unclestu, gave us a good background.

I do not do religious writing. See your clergyman for that. I discuss audio up here in terms that make sense to me.

If you are Paully, whether you excuse my off topic comment or not, the amp with the two tubes you selected will likely need a redesign. That is what YOU should be thinking about now.

By the way, I think both the tubes you picked are glorious, among my all time favorites. Your future problem is, it will not work real WELL / OPTIMALLY as a TWO stage amp unless pushed hard, simply not enough gain ! You should address that before you build.

So, all this public Forum planning, bandwidth, time, and your out-of-pocket expense is wasteful IMHO.

In Reply to: RE: Question posted by deathtube 667 on May 15, 2012 at 07:18:59

whats the bet the anon troll has a system full of high dcr sloppy amps and no money to upgrade them. So he would rather live in de nile

any way latterly I have been contemplating that the ax7 and el84 are the finest audio tubes ever built and given you where a great amp builder you shouldn't really need anything more.One day when I am bored of dht's I am going to build another el84 SE amp with the best power supply I can afford. It will have feedback and maybe even global feedback around the trans and it may even have 2 coupling caps and 2 ax7 driver stages. I once found a vintage jap rapar el84 amp for a friend. It had feedback 2 ax7 gain stages with tone controls. And we hooked that amp up and wow. 12ax7 el84 the ultimate desert island tubes and budget tubes too.

Those guys that made those tubes made them for audio with feedback and when used right they sure do sing.

In Reply to: RE: Question posted by TubeBuilder on May 16, 2012 at 04:58:23

I agree that the EL84 can be a great sounding valve. I don't agree that Global feed back is necessary to run them as Pentodes with pleasing results.

I have been implementing feedback between the OPT Secondary and the Cathode with very good results. I love the sound of a well tamed Pentode. I would not do this with a Triode mainly because it's not necessary secondly a 60 V bias voltage across the Secondary of your OPT is not especially safe...The Bias voltage of an EL84 and EL34 is relatively low...A cathode winding in the primary would be nice...I've not thrown the cash at one of these animals to date.

In Reply to: RE: Question posted by View from under the bridge. on May 16, 2012 at 05:36:43

Hey, you best re-read my original post in this thread. I clearly state it is off topic. If that is "trolling" so be it. I was trying to help the builder, by addressing the bigger design perspective.

Is that too difficult for anyone to envision and see????

Also, any mention of "black insulation, and 12AX7s", was introduced to this thread by Paully himself, not me! Any previous posts I did on black insulation was the result of information posted by Unclestu, and I tend to still believe him fully on this subject. What you, or others want to do about black insulated wire is totally up to YOU.

My point is, IMHO, a single Type 76 is too low a gain ( mu of 13.5 as I recall) to drive the DHT finals optimally.

So far, only Deathtube 667 has contributed anything on the question of gain, where he states he found a 12AT7 was an improvement in musical presentation over a lower mu tube.

So... when do we stop this silly BS of YOU (and Paully) pointing fingers and making off-topic accusations, and return to the design idea that the gain with a single Type 76 front end might be too low for a two stage amp??

In Reply to: RE: Question posted by drlowmu on May 16, 2012 at 07:03:46

You're too much, Jeff! You hijack this thread to suit your own agenda and then have the gall to say: "So... when do we stop this silly BS of YOU (and Paully) pointing fingers and making off-topic accusations, and return to the design idea that the gain with a single Type 76 front end might be too low for a two stage amp??"